NEW YORK (Reuters Health) - The risk of lung cancer in
people exposed to asbestos falls after exposure to the toxic
substance ends, a new study in Italian asbestos cement workers
shows.

And while the risk of mesothelioma in the pleura -- the
tissue lining the lung surface and chest wall -- also declined
after exposure ended, the workers' risk of mesothelioma in the
peritoneum -- the tissue lining the abdominal cavity --
continued to climb, Dr. Corrado Magnani of the University of
Eastern Piedmont in Novara, Italy, and colleagues found.

Magnani and associates followed 3,434 male and female
workers in order to understand the long-term risks of
asbestos-related disease. All were working at the plant in 1950
or had been hired between 1950 and 1986, when the plant halted
production.

Both men and women in the group were at increased risk of
dying from any cause, any type of cancer, lung cancer, and
pleural and peritoneal mesothelioma, the researchers found.

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Women were also at greater risk of ovarian and uterine
cancer. But the risk of cancer of the larynx (voice box) or
cancer of the digestive tract was not greater than would have
been expected in the general population.

Overall, the researchers found, that over a 41-year period,
there were 480 excess deaths due to cancers and to asbestositis
-- a chronic inflammation of the lungs due to asbestos
exposure.

The risk of pleural mesothelioma rose steadily with years
of asbestos exposure, the researchers found, but began to
decline 50 years after exposure had ended.

The risk of lung cancer was highest for men 30 to 39 years
after the end of exposure, and for women in the 20 to 29 years
after exposure ended, and then began to decline. But the risk
for peritoneal mesothelioma continued to rise even 40 years
after exposure had ended.

These findings, note Magnani and colleagues, suggest that
there may be different mechanisms by which asbestos exposure
causes mesothelioma in the pleura and the peritoneum.